1. Field of the Invention
The present invention relates to a display device, and more particularly, to a quad-type display device having a pixel comprising red, green, blue, and white sub-pixels, and a driving method thereof.
2. Discussion of the Related Art
Until recently, display devices generally employed cathode-ray tubes (CRTs). Presently, many efforts are being made to study and develop various types of flat panel displays, such as liquid crystal display devices (LCDs), plasma display panel (PDPs), field emission displays, and electro-luminescence displays (ELDs), as substitutions for CRTs because of their high resolution images, lightness, thin profile, compact size, and low voltage power supply requirements. In addition, such a display device displays video information with a plurality of pixels arranged in a matrix type. In general, a pixel has red-color, green-color, and blue-color sub-pixels.
FIG. 1 is a view of a RGB-stripe-type display device according to the related art. In FIG. 1, a RGB-strip-type display device includes gate and data lines “GL” and “DL” crossing each other to define a sub-pixel region, such that red-color, green-color and blue-color sub-pixels, “R”, “G”, and “B,” are arranged along a row line to constitute a pixel.
A display device also may be, instead of the RGB-stripe type, a RGB-delta-type or a RGB-mosaic-type. Further, a quad-type display device having red-color, green-color, blue-color, and white-color sub-pixels also has been used.
FIG. 2 is a view of a quad-type display device having red, green, blue, and white sub-pixels to the related art. In FIG. 2, red-color, green-color, blue-color, and white-color sub-pixels, “R”, “G”, “B”, and “W,” constitute a pixel “P”. In addition, a plurality of pixels “P” are arranged in a matrix. Since the quad-type display device further has a white-color sub-pixel “W”, the quad-type display device has a higher white luminance than the RGB-stripe-type display device.
However, the quad-type display device has a reduced aperture ratio, requires more data and gate lines, and needs more driving circuits. For example, if a display device has XGA resolution (1024×768), the RGB-stripe-type has sub-pixels of 1024×3 columns and 768 rows and the quad-type display device has sub-pixels of 1024×2 columns and 768×2 rows. Because the quad-type display has more sub-pixels than the RGB-stripe-type, an area of each of the sub-pixels of the quad-type display device is smaller than an area of each of the sub-pixels of the RGB-stripe-type display device. In addition, the quad-type display device needs 1024×4 data lines and 768×2 gate lines to drive the sub -pixels, while a RGB-stripe-type display device having XGA resolution has 1024×3 data lines and 768×2 gate lines. Accordingly, the quad-type display device needs more data and gate lines than the RGB-stripe-type display device, thereby needing more driving circuits.